The in-house crew more-or-less works for free. The outsourced one? Who the fuck knows?
In the past I know WT has provided a private residence for an attorney and his family who relocated while he volunteered his time at Patterson.
I also know of local JW attorneys (those who must had disobeyed counsel about higher education) have assisted in insignificant local cases and likely did so free of charge.
The private (non-JW) attorneys that are hired for cases that risk huge settlements/judgements are likely paid hourly, just like anyone else pays them. Perhaps they get a discount for their "charitable" status, or even pro bono work, but I suspect they "lawyer up" and just pay the price for attorneys who specialize in issues like CSA.